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I have a VMware ESXi host that runs 2 virtual machines, and we will be adding two more to it. One VM is our main DC/DHCP/DNS/Fileshare/SVN server, and the other is a development testing VM. The two additional ones that will be added soon will also be development machines.

My question is this: we have two LAN ports on the VM host. I know I will want to add at least one or two more NIC cards to balance the load, but the server is behind a switch. Will this cause extreme bottlenecking for others in the office? And is it worth it to move the server into our closet which has direct access to about 20 more ports on the network?

I ask this because it seems like a bottleneck would happen when you have 15 people trying to access one server over one cable that gets split to 4-5 destinations.

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up vote 1 down vote accepted

Honestly, I would be surprised if 4 servers over two NICs would actually cause a bottleneck.

Obviously it depends on the load these servers are receiving.

I have two ESXi servers both having two Gigabit NICs to serve a dozen servers each and never had the NICs usage go above 30%.

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I've been monitoring the network usage for the past few hours, it stays pretty steadily around 10%-15% in our current setup. I am remoted into both VMs and working out of both and if we still have ~85% of our network being unused, then two more VMs shouldn't cause too much of a bottleneck when we implement them to ESXi. – Alexander Miles Apr 27 '11 at 18:33

All of this really does depend on how busy your existing network links are, in a single-ESX-host scenario all of your intra-VM traffic is handled internally without any traffic leaving the host. If your host ports themselves are busy then certainly adding more trunk members between your host and your switches will help yes, so will placing the server at the right point in your network but without quite a lot of extra detail about your network layout it would be hard for us to give you a better answer than this. You really need to find out how busy your links are right now though.

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